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NR981 Series Residential Tankless Water Heaters

by Noritz

Unlike with a conventional tank-type water heater, the hot water is always there when you need it with a tankless water heater. With a tankless water heater, water is heated as it passes through the unit so you will always be using a fresh supply of water. A Noritz Tankless water heater provides a continuous flow of hot water, so there's no need to suffer through a cold shower if you're the last one out of bed, and there will always be plenty of hot water instantly ready for other uses when you're done.

Noritz NR981 Tankless Water Heater

These tankless water heaters feature:
  • Designed for mid-sized homes with up to 3 showers, this space efficient, wall-hung unit will help assure you never run out of hot water
  • Indoor/outdoor models (SV) include a power cord and may be installed either inside or outside of the home and are designed to be vented horizontally or vertically
  • Outdoor units (OD) are designed for installation outside of the home and require no additional venting as a horizontal vent is built right into the unit
  • Designed to accept a quick-connect cable, allowing two units to link together to satisfy higher flow demands
  • Dual flame burner minimizes temperature fluctuations
  • Fully modulating design and automatic air regulator monitors internal temperature and adjusts burner according to need, providing accurate and efficient response to hot water demands
  • Direct ignition means no standby pilot light to waste energy
  • Commercial grade heat exchanger for superior durability
  • Built in freeze protection for additional peace of mind
  • Thermal fuse offers automatic overheat protection
  • Self-diagnostic onboard computer system, combined with the included digital remote, provides ease of maintenance and temperature adjustment
  • Battery back-up compatible
  • Recirculation compatible
Noritz NR981 Tankless Water Heater Specifications:
  • Thermal efficiency: 84%
  • Flow rate: 0.5-9.8 GPM - click for flow rate chart
  • Temperature settings: 100-180°F (14 options)
  • Gas connection: 3/4" NPT
  • Water connections: 3/4" NPT
  • Water pressure min: 15 psi, max: 150 psi
  • Gas input min: 11,000 BTU, max: 199,900 BTU
  • Gas supply pressure: NG 4.0" - 10.5", LP 8.0" - 14.0"
  • Weight: 47 lbs
  • Air supply/exhaust: Power vented
  • Ignition: electronic (no pilot light)
  • Electrical supply: 120V (60Hz)
  • Actual electrical consumption in Watts:
      •SV Model: NG: 62W, LP: 75W, freeze protection: 145W
      •OD Model: NG: 64W, LP: 77W, freeze protection: 145W
  • Actual electrical draw in Amps: less than 2 Amps
      •Operation: 0.6 Amp
      •Standby mode: 0.06 Amp
      •Freeze prevention: 1.3 Amps
  • Dimensions: 23.6"h x 13.8"w x 9.4"d
  • Uses 4" Category III stainless steel venting
Model Number Description Natural Gas Propane
NR981-SV Indoor/Outdoor Tankless Water Heater $1,440.25 $1,441.69
NR981-OD Outdoor Installation Tankless Water Heater (only) $1,435.19 $1,436.70
Due to weight and to ensure safe delivery, these items ship by truck and have a $175 additional shipping fee per freight item.
Please select your type of address: Commercial -or- Residential

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Complete your installation with Noritz stainless steel venting!

Noritz NRC98 Series Condensing Residential Tankless Water Heaters

The condensing version of the NR981 tankless water heater recaptures waste heat to heat a secondary stainless steel heat exchanger to raise the incoming water temperature before it passes through the main copper heat exchanger. This highly efficient process both heats water and cools exhaust gasses, allowing this unit to be used with PVC venting material and increasing the thermal efficiency to 93%. So, not only is the venting less expensive, but the heater itself uses less fuel - 16,000 BTU (min) to 180,000 (max).

Model Number Description Natural Gas Propane
NRC98-DV Direct Vent Tankless Water Heater (only) $1,422.61 $1,423.50
NRC98-OD Outdoor Installation Tankless Water Heater (only) $1,421.43 $1,422.76
Due to weight and to ensure safe delivery, these items ship by truck and have a $175 additional shipping fee per freight item.
Please select your type of address: Commercial -or- Residential

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Accessories for Noritz Tankless Water Heaters
Description Price & Quantity
Quick-Connect Cord
Use the Quick-Connect cord to quickly and easily connect two identical units to satisfy greater hot water demands
Quick-Connect Cord - connects two identical units $29.70

Pressure Relief Valves
A pressure relief valve is required for all tankless water heaters. In some areas, a temperature and pressure relief valve is required. Check your local plumbing code for more information.
Pressure Relief Valve - Brass - 3/4" - 150 PSI $12.96
Temperature and Pressure Relief Valve - up to 200,000 BTU $49.33

Gas Connectors - view more gas connectors
Stainless Gasflex - 1" OD (3/4" ID) x 24" - with adapter to 3/4" FIP x 3/4" MIP $33.15
Gas Ball Valve 3/4" $7.54

Ball Valves - view more ball valves that meet "Federal Safe Drinking Water Act Standards"
Ball Valve - 3/4" FIPS
Order 10, 50, 100 or more for extra savings!
Ball Valve - 3/4" Sweat
Order 10, 50, 100 or more for extra savings!
Stainless Steel Nipple - 3/4" IPS x 1-1/2" Long $3.80

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Water Connectors - click here for more flexible water supply lines
Flexible Corrugated Stainless Steel Water Connector - 3/4" FIP x 3/4" FIP - 18" Long $6.78
Flexible Corrugated Stainless Steel Water Connector - 3/4" FIP x 3/4" FIP - 24" Long $7.53
Flexible Corrugated Copper / Stainless Steel Water Connector - 3/4" FIP x 3/4" Nom Sweat - 18" Long $6.93
Flexible Corrugated Copper / Stainless Steel Water Connector - 3/4" FIP x 3/4" Nom Sweat - 24" Long $7.55

"The Isolator" Isolation Valves - Includes pressure relief valve
Complete inlet/outlet valve system that provides everything you need for a secure installation including full port testing and flushing of the system with easy to install union connections. Includes pressure relief valve. Meets Federal Safe Drinking Water Act Standards
Isolation Valve - Set   (Hot & Cold)   3/4" FIP Union x 3/4" FIP $94.89
Isolation Valve - Set   (Hot & Cold)   3/4" FIP Union x 3/4" Sweat $94.96

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Related Items and Accessories

Please note: For potential safety reasons, we do not recommend using PVC to vent gas tankless water heaters. For the best results, we recommend using Category 3 stainless steel gas vent pipe for all gas tankless water heaters.

Common Plumbing Terms
FIP Female Iron Pipe (NPT threads)
MIP Male Iron Pipe (NPT threads)
NPT National Pipe Thread
FNPT Female National Pipe Thread
MNPT Male National Pipe Thread
Nom. Nominal: Used to describe copper pipe and fittings in plumbing. Refers to the inside diameter of the pipe which varies by thickness of the pipe
Sweat Copper pipe solder fitting

Frequently Asked Questions

Q. "How does a tankless heater provide hot water without a storage tank?"
A. Tankless water heaters heat on demand. The water is heated as it flows through the unit. Automated valves control water and gas flow so that your water comes out at the temperature you set it to.

Q. "Your products specify the 'temp. rise' based on the GPM flow; what do you mean by this?"
A. Temperature rise is the amount the heater raises the temperature of the incoming water, based on the flow rate shown of that water.

Q. "What's the difference between a conventional flue and a direct vent?"
A. A conventional flue is what most people are familiar with. It typically consists of a double-wall flue pipe going from the top of the heater through the roof, venting outside. The fixture draws its combustion air from the space around it (utility room, garage, hallway, etc.). A direct-vent unit vents and draws its combustion air through a specially designed pipe from the outside via an adjacent wall.

Q. "What do you mean by commercial grade heat exchanger?"
A. This Noritz tankless hot water heater has a heat exchanger made with Type K copper piping, which is 25% thicker than the average heat exchanger in most tankless water heaters. Since the heat exchanger is what conducts the heat from the burner to the water, it is subject to a lot of stress. Having thicker copper means that the unit is more durable and will heat more water before the heat exchanger needs to be replaced. This Noritz residential tankless water heater has a 12 year limited heat exchanger warranty for residential use.

Q. "Can I use PVC to vent the NR981 as well as the condensing tankless water heaters?"
A. No. The temperature of the exhaust is too high to safely use PVC as venting material for standard tankless water heaters. We never recommend PVC as venting even where the ideal exhaust temperatures would technically allow it due to a much higher incident of dangerous issues associated with PVC venting on poorly-maintained gas tankless water heaters.

Q. "Okay, but the NRC98 has PVC flue adapters, so I have to use PVC with that one, right?"
A. The manufacturer of the NRC98 condensing tankless water heater states that it is designed specifically for use with PVC or CPVC 3" or 4" venting materials. We recommend a stringent maintenance schedule to maintain the efficiency of your condensing tankless water heater and prevent potential issues with PVC venting. Specifically, be aware of scaling on the heat exchanger which lessens the efficiency of the water heater and allows higher temperature exhaust to escape. Depending on your water quality, an acid neutralizer and/or water softener may be helpful in protecting your investment in a condensing tankless water heater and preventing exhaust temperatures from exceeding safety parameters for PVC venting.

Q. "How does the Water Heater Scale Inhibitor System prevent corrosion?"
A. It forms a thin protective layer on the inside of pipes and metal parts. This film or layer is microscopic in thickness and will not build up over time.

Q. "What are the best reasons to install a Scale Inhibitor System?"
A. A Scale Inhibitor System helps protect the system by reducing scale buildup and adding to the longevity and efficiency of the heater.

Q. "This is a water heater. Why would I need a battery backup?"
A. Since this tankless water heater has direct electronic ignition, power is needed to create a spark, as well as run the computer and remote. A battery backup is not required, but may be beneficial if you are in an area where there are frequent power outages as this would help provide power to your Nortiz tankless hot water heater for a short time. When choosing a battery backup, which can be purchased locally, please note it must produce a pure sine wave. Also, battery backups are only for indoor units that are plugged in as opposed to hardwired.

Q. "Will an instantaneous water heater save me money on my utility bills?"
A. In many applications you can see a savings. There are some variables that could reduce the amount you save. One example is you will not run out of hot water, so longer showers could cut into your savings. Also, the cost of electricity, propane and natural gas in your area will affect the amount of money saved. The higher the cost for the energy type used to heat your water, the quicker you can recover the higher initial cost of installing a tankless versus tank style water heater.


  • You will never run out of hot water. "You want an hour long shower? No problem!"
  • Electric units can be installed at the point of use.
  • You're not paying energy costs to heat water 24 hours a day.
  • They're easy to install.
  • Our electric units don't require a T&P valve (no tank!) - if code allows
  • Installing a tankless water heater can indeed be a bonus to the environment (why should we choose wastefulness when we're talking about finite natural resources?)


  • They all need a minimum flow rate & pressure to turn on.
  • The faster water flows through them, the lower the temperature rise. So, if you expect to take a shower while the clothes washer is running, you will need to select a unit sized to your maximum hot water flow requirements. (Gas units generally handle this a little better than electric models)
  • Electric units need heavy gauge wire. Example: the 9.5kw must have 8ga wire and a 50amp breaker.
  • Gas units need a much larger, special flue pipe and larger gas supply than a conventional water heater.
  • At times they can produce very hot water. It's easier to get scalded.
  • Gas units are more complicated than a conventional water heater.
  • With some brands, parts are hard to find (not a negative if you originally purchase from us, as we like to carry parts for the units that we sell).

Tankless water heaters have their place. They're not "the answer" to every hot water need, but if they're used correctly they can be the solution to many of them.

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